Many US producers have led customers thru the costing models, noting freight, quality, material variations, in transit losses, increased need for documentation and communications and increased management costs plus much more. Most guys will compete on an apples to apples basis, but quotes must be detailed for many to see the problems and the spreadsheets done for the purchaser to see the differentials.
I can state from experience though that the US OEM's really didn't believe in their own cost models - sort of a "torpedos be damned" attitude. For GM, their growing manufaturing and sales base in China trumped all short term costs. The real goal was to develop the local manufacturing base in China, then do car assembly, then engineering ... until an entire car can be engineered, sourced and built there. This makes sense longterm, but the short term plan was to import the parts back into the US for assembly here, and the near term costs were simply overwhelming.
As a Chinese moldmaker,I have talked about this topic with one of my American partners, yes,he found the cost in China has raised those year, while he
told me that the quality and effcient has improve as well .while, anyway, it's a problem
for our cooperation, then we discuss how to low the cost ,so we discuss the molds,
as Chinese standard and skillful technical to build the molds is really a big discount
(eg, an USD8000 mold ,in Chinese standard would be USD4000-5000),because Chinse
product is always share a good reputation ,yes,we focus on the product ,the shrinkage,the surface artistic and other factors ,then we make a nearly USD20,000 deal.
which it's helpful for Chinese and USA partners .Of course, it suits the small parts and
the quantity should be make sure big enough, anyway, Chinese factory should living on